In a related art, a moving object equipped with a wireless communication device moves along a road and detects strength of radio waves transmitted from a base station. The moving object equipped with a wireless communication device is also known as a mobile station. The strength of radio waves detected by the moving object is expressed as a positioning locus of the moving object. In this related art, a position of the moving object is estimated by a map matching. In the map matching, the positioning locus of the moving object is compared with a preliminarily prepared coverage map in order to estimate the position of the moving object.
Specifically, as disclosed in JP 2013-257306 A (corresponding to US 2013/0310067 A1), in the coverage map, an area or a road having a high similarity with the positioning locus is extracted. The current position of the mobile station is specified based on position information of a predetermined feature point included in the extracted area or in the extracted road and relative position information indicating a relative position relation between the feature point and the matching point. Herein, the matching point corresponds to the current position of the moving object and also corresponds to the end point of the positioning locus.
In the related art, in some cases, the feature point does not exist due to a locational environment of the base station or the feature points are not arranged at proper intervals. In these cases, when the position specified on the coverage map generated based on the detected signal strength is matched with a position existing on a map including positioning coordinates for position detection, an accuracy of the position matching may be degraded.